Preparation, electronic structure, and chemical bonding of lead-free (1 − x)(K0.5Bi0.5)TiO3-xBaTiO3 solid solution

Abstract

Polycrystalline lead-free (1 − x)(K0.5Bi0.5)TiO3-xBaTiO3, ((1 − x)KBT-xBT) (x = 0.00, 0.08, 0.12) ceramics were synthesized via solid-state reaction method. The powder X-ray diffraction (PXRD) and structural refinement results confirm that a single-phase tetragonal structure with space group P4mm. Charge density distribution inside the unit cell of (1 − x)KBT-xBT was investigated by the maximum entropy method. Charge density analysis reveals the reduction in ionic nature along K/Bi–O bond and enhancement of covalent nature along Ti–O bond with the addition of BaTiO3. The charge density distribution studies done using maximum entropy method for (1 − x)KBT-xBT have not been done so far. The surface morphology study was done using scanning electron microscopy (SEM). Energy dispersive X-rays spectra (EDS) were used to investigate the elemental compositions present in the system. The dielectric constant and loss tangent were studied as a function of frequency. The dielectric constant and loss were decreased with increase of frequency. Room temperature dielectric constant (ɛ) and loss (tan δ) were measured for x = 0.00 about 511 and 0.51, respectively, at a frequency of 10 kHz.